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13th march 2008
David Mearns - Search Director, The Finding
Sydney Foundation
After our early problems I am very pleased with how the search has
progressed over the past couple of days. The Williamson & Assoc's
SM30 side-scan sonar search system was selected for this project
because it is one of the few commercially available sonars of its
type in the world that is ideally suited to the specific
requirements of this search. It can also be operated to a depth of
6,000 metres, which is well beyond our needs.
The
SM30 has two transducers, scanning to either side of the towfish,
that operate at a frequency of 27 kHz and 30kHz. These low
frequencies (mismatched to prevent acoustic crosstalk) enable us to
search an area approaching 6km in swath width, whilst still being
able to detect small man-made objects like 55-gallon drums. The SM30
has been successfully used on a number of important shipwreck search
projects including location of the side-wheel steamer SS Central
America and the submarine USS Grunion. The Grunion website has all
the details of this interesting project
(http://www.ussgrunion.com/).
I
have know Art Wright, the Party Chief of the W&A search team, for 20
years and it is good to be back at sea with him. We first met
working on a landmark project for the oil and gas industry off the
coast of Santa Barbara, California where we conducted the first ever
pipeline route survey using a deep-tow multi-beam sonar. Like me,
Art enjoys search projects more than industry projects and he has
been dipping into our library of books on the battle between
Kormoran and Sydney.
Glenys McDonald - Director, The Finding Sydney Foundation
(Observer)
Today, I have spent much of my time in the survey room with the
Williamson & Assoc's crew. I took the opportunity to sit in the hot
seat flying the fish for a few precious moments myself. The
technology is incredible. You can see exactly where you are, the
precise GPS position, water depth, altitude of the fish etc, all of
which is printed out and saved on computer file, where track lines
and positions can be compared.
It
is hard to comprehend that we are scanning 3000 metres of sea bed on
either side of our track. I can recommend the leisurely pace of 3
knots, although it takes nearly a good 24 hours to complete one
track line.
The
work is ongoing 24 hours and night and day has become a little
blurred. It does not matter out here if I go to bed at midnight or
2am. The Williamson crew changeover is at midnight and midday.
David's off shift operator Robert works a twelve hour shift
commencing at 6 pm, but David Mearns is on deck long hours after his
shift officially ends.
John Perryman - Senior Navy Historian (Observer)
Today we completed our north-south run down line number 9 of the
search box where we continued to see a mixture of sporadic
geological features such as rocky outcrops and depressions as well
as large tracts of featureless sea bed. Travelling at between 2-3
knots is slow going, but that is the nature of the work with the
SM30 sonar equipment streamed astern of us on anything up to 9,500
metres of cable. With freshening winds we are now repositioning for
further runs throughout the search area.
Historical anecdote
HMAS Sydney (II) had four commanding officers during her six year
commission in the Royal Australian Navy (RAN). The first was Captain
J.U.P. Fitzgerald, Royal Navy (RN), who commissioned Sydney in
England on 24 September 1935. He was succeeded by Captain J.W.A.
Waller, RN in 1937, who remained in command until 16 November 1939
at which time Captain J.A. Collins, RAN assumed command. Collins was
a graduate of the Royal Australian Naval College and the first
Australian officer to command the light cruiser. It was under the
command of Collins that Sydney captured the hearts and minds of the
Australian population through her exploits in the Mediterranean
theatre. Notably for crippling the Italian cruiser Bartolomeo
Colleoni, and her spirited pursuit of her consort, the cruiser
Geovanni Delle Bande Nere.
On
return to Australia, Collins was relieved by Captain J. Burnett,
RAN, on 14 May 1941. Captain Burnett went down with his ship
following the fierce action with the German raider Kormoran on 19
November 1941.
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